Here's my list of 10/10 metal albums, cross-posted from another thread, since it seems more on-topic here... note, this is in no particular order because, well, fuck orders, they aren't metal

I basically typed these in a stream-of-consciousness style and it covers a vast variety of sub-genres as well. I also limited myself to 1 album per band, but as I said in the other thread, many of these bands have more than one great album.
Iron Maiden - Seventh Son of a Seventh Son
Mercyful Fate - Don't Break the Oath
Judas Priest - Stained Class
Black Sabbath - Master of Reality
Summoning - Minas Morgul
Skyclad - The Silent Whales of Lunar Sea
Candlemass - Epicus Doomicus Metallicus
Morbid Angel - Altars of Madness
Manilla Road - Crystal Logic
Slayer - Show No Mercy
Overkill - The Years of Decay
Rotting Christ - Non Serviam
Therion - Theli
Deströyer 666 - Phoenix Rising
Dissection - Storm of the Light's Bane
Dark Tranquillity - The Gallery
Samael - Blood Ritual
Blind Guardian - Imaginations from the Other Side
Jag Panzer - Thane to the Throne
Pentagram - Relentless
King Diamond - Abigail
Bathory - Hammerheart
Sepultura - Beneath the Remains
Helloween - Walls of Jericho
Running Wild - Black Hand Inn
Accept - Restless and Wild
Desaster - Hellfire's Dominion
Absu - Tara
Death - Symbolic
Venom - Black Metal
Pagan Altar - Lords of Hypocrisy
Pantera - Power Metal (hehe)
Amorphis - Tales from the Thousand Lakes
Anacrusis - Screams and Whispers
Virgin Steele - Invictus
Moonspell - Wolfheart
Type O Negative - Bloody Kisses
Melechesh - Emissaries
Helstar - Nosferatu
Satan - Life Sentence
Metal Church - Metal Church
Kreator - Pleasure to Kill
Sodom - Agent Orange
Megadeth - Rust in Peace
Artillery - By Inheritance
Tiamat - Wildhoney
In the Woods - Heart of the Ages
Storm - Nordavind
Einherjer - Blot
Falkenbach - ...magni blandinn ok megintíri...
Moonsorrow - Voimasta ja kunniasta
Ancient Rites - Dim Carcosa
Hollenthon - With Vilest of Worms to Dwell
Varathron - His Majesty at the Swamp
Natur - Head of Death
Sabbat - Envenom
Loudness - Thunder in the East
Testament - The Legacy
Anthrax - Among the Living
Dio - Holy Diver
Saxon - Denim and Leather
Angel Witch - Angel Witch
Immortal - At the Heart of Winter
Behemoth - Satanica
The Kovenant - Animatronic
Arkona - Vo Slavu Velikim!
Cruachan - Tuatha na Gael
Mithotyn - Gathered Around the Oaken Table
Falconer - Falconer
Metallica - Kill 'Em All